Electric heat regulating element



March 27, 1934. L LUDWIG 1,952,445

ELECTRIC HEAT REGULATING ELEMENT Filed May 26, 1930 L 00 1 5 L z/ w yLow W l uxdwim Patented Mar. 27, 1934 UNITED STATES PATENT OFFICEELECTRIC HEAT REGULATING ELEMENT Louis Ludwig, Brooklyn, N. Y.

Application May 26, 1930, Serial No. 455,759

1 Claim.

My invention relates to electric heating elements such as are used inso-called sun bowl heaters, for example. It has for its main object toprovide a heating element containing a plurality of resistance elementsof different resistances, so that various amounts of heat may beobtained by using one or another of the resistance elements, or bycombining them all. An other object is to provide a heat-regulatingelement of simple construction, easy to manipulate, and comparativelyinexpensive to manufacture.

These and other objects and advantages will be readily understood fromthe following description and from the accompanying drawing of apreferred embodiment in which, however, modifications might be madewithout departing from the scope of the invention. In the drawing Fig. 1is a side elevation of my invention,

Fig. 2 a cross-sectional side elevation,

Figs. 3, 4 and 5 end views showing the switch mechanism in diiferentpositions, and

Fig. 6 an enlarged sectional view taken on line 6-6 in Fig. 5.

Referring now to all the views, the device consists of a body member 10made of insulating and heat resisting material. One end 11 of the bodymember is threaded and provided with a metal ferrule 12, adapted to beinserted in an electric socket. The other end of the body memberconsists of an inverted, hollow frustum 13. A relatively short neck 14separates the two ends. Two helical grooves are moulded on the outsideof the frustum shaped end and in these grooves two resistance coils 15and 16 are supported. The

end 17, of the coil 15, is connected to a metal contact 18 which is inturn connected to the ferrule 12. The end 19, of the coil 16, islikewise connected to a metal contact 20 which is also connected to theferrule. Two lugs 21 and 22 are moulded on the upper end of the bodymember diametrically opposite each other. They are provided with groovesin which metal contacts 23 and 24 are secured. The upper ends 25 and 26of the resistance coils are connected to these contacts. These wire endsare contained in slots 27 and 28 which are formed on the outer edge ofthe body member.

A metal rod 29, one end of which is threaded, is secured in the axialhole 30 of the body memher by means of the nuts 31 and 32. The upper end33 of this rod is of reduced diameter and provided with a collar 34. Aswitch member 35, having four flexible arms 36, 3'7, 38 and 39, isattached to a handle knob 40 which is rotatingly mounted on the end 33.When the knob is turned the arms contact with the metal contacts 23 andThe outer ends of the arms are slightly curved to facilitate theirmovements over the edges of the lugs 21 and 22. illustrated in theenlarged view Fig. 6.

This is plainly In the 29, switch plate 35,

arm 39, coil 16, contact 20 and ferrule 12. As the coil 16 is of acertain resstance, a certain amount of heat is given off. If the knob isnow turned in the direction of the arrow so that the arm 37 engages onthe contact 24, as shown in Fig. i, the current will flow through coil15 instead of through coil 16. As the coil 15 has a different resistancethan coil 15, a d fferent amount of heat is given off. If the knob isagain turned in the direction indicated the arm 38 will engage withcontact 23 and the arm 36 with contact 24. In this position the currentwill flow through both coils and the heat given oif will be the combinedheat of both coils.

While I have described and illustrated a heating element having a bodymember of the shape most commonly used, it will be understood that myinvention may be applied to heating elements of other shapes.

Likewise, while I have only shown two coils, additional coils might beemployed.

ance elements of different resistances wound helically upon the bodymember in spaced relation to each other and each having one endconnected to the metal ferrule, a switch disc rotatingly mounted on theouter end of the metal rod 1 and electrically connected therewith, andthe switch disk provided with two oppositely-disposed arms forcontacting with the other ends of both of the resistance coils so as toconnect them in parallel and two other arms disposed unequi-distant fromthe first-mentioned arms for likewise connecting with the ends of thecoils, but for connecting one or the other only at a time in thecircuit.

LOUIS LUDWIG.

